Air insulation techniques provide users with a fully serviceable, high voltage power supply that is light and portable, and can be maintained down to component level, achieving a very low long term cost of ownership during a protracted lifespan.
High voltage multiplier designs capable of producing very high voltages – up to 500kVdc from a Glassman product – are also likely to generate corona, arcing and ionization. Therefore, designers must select a suitable dielectric medium in which to insulate the high voltage components employed within the multiplier circuit; they must also pay careful attention to the mechanics, production costs, long term reliability and ease of servicing.
Epoxy resins, silicon rubber and oil are all in common use as dielectric mediums within high voltage multiplier designs. However, Glassman is unique in using air as the primary dielectric medium in all of the company’s standard high voltage structures. For the vast majority of applications, this technique has many advantages, when compared to the use of solid encapsulation or dielectric oil.
One of the major benefits is the ease of serviceability. Since high voltage multipliers are constructed using discreet components on printed circuit boards, all of the components are accessible and therefore easily replaced in the event of failure. However, the use of a solid encapsulation renders the HV assembly unserviceable. Therefore, should a failure occur, the complete assembly is likely to require replacement, which can be both expensive and time consuming as this assembly is likely to be a production item with a six or eight week lead time. If oil is employed, then the component parts can be accessed, although oil can be messy and difficult to work with. Oil also needs to be changed at regular intervals to maintain its purity; this may prove costly to the user, especially if it means shutting-down a manufacturing process, thereby losing valuable production time.
Another advantage of air insulation is reduced weight and therefore greater portability, which not only benefits personnel working with the power supply, but will also reduce freight costs. This can be significant, especially if the power supply is used within OEM equipment that will be shipped in significant quantities over long distances.
Glassman High Voltage Inc. pioneered the use of air insulated high voltage multiplier assemblies within standard high voltage regulated dc power supplies. The use of printed circuit boards for the construction of the company’s high voltage multiplier assemblies guarantees consistent and reliable component placement, ensuring all component spacing is correct to produce acceptable voltage gradients. All components are rated for operation in excess of 150% of the specified voltage for each power supply model, thereby delivering long term reliability. This design philosophy has helped to reinforce Glassman’s global reputation for high quality, high reliability power supplies.
Glassman boasts one of the widest ranges of standard high voltage dc power supplies available and the component accessibility of the company’s air insulated high voltage multiplier designs means that it is relatively simple to modify the circuits. This enables the company to easily adapt its designs to meet the often-challenging requirements of individual applications, offering a semi-custom design service and broadening the product capability even further.
Glassman high voltage power supplies are produced within a 6000m² U.S. manufacturing facility and headquarters. This ensures consistent and reliable build quality, without the need to rely upon third party offshore manufacturing facilities. Standard high voltage PSUs ranges are available from 0-1kVdc to 0-500kVdc, with power output capabilities from 15W to 50kW, which will soon be extended to 100kW. Standard features on many Glassman products include active arc protection circuitry, selectable constant current / current trip function, variable slow start ramp function, analogue and digital remote programming facilities, and USB and RS232 connectivity with an optional Ethernet capability.
All standard Glassman power supplies include a three year parts and labour warranty, with a one year warranty on OEM and modified versions. The company has a global sales and technical support network; Glassman Europe Limited, the European headquarters for Glassman High Voltage Inc, is headquartered in the United Kingdom.
